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Aim: Effect of nanoparticles (NPs) loaded methylene blue (MB) mediated photodynamic therapy (PDT) on caries-affected dentin (CAD) against S.mutans, smear layer (SL) elimination, and shear bond strength (SBS) of single bottle 7th generation adhesive., Methodology: Sixty human molars with carious lesions were selected. Samples were randomly allocated into four groups, based on the disinfection regime (n = 11) Group 1-(CHX), Group 2-(MB-PDT), Group 3-(MB-CNPs-PDT), and Group 4-(MB-TiO 2 NPs-PDT). Following disinfection S.mutans' survival rate was assessed using the pour plate method. Five specimens from each disinfection group were subjected to SL removal assessment using a scanning electron microscope (SEM). Bonding of 7th generation adhesive and composite restoration was performed on ten samples from each group. Artificial aging of the bonded samples was performed followed by SBS and failure mode analysis using a universal testing machine and stereomicroscope respectively. One-way analysis of variance (ANOVA) and Tukey post hoc test were used to analyze the data., Results: Group 3 (MB-CNPs-PDT) treated CAD surface unveiled the lowest survival rate (0.12 ± 0.02 CFU/mL) of tested bacteria, maximum SL removal (1.21 ± 0.35), and highest bond strength (13.42 ± 1.05). However, Group 1 (CHX) treated specimens displayed the highest survival rate (0.53 ± 0.11 CFU/mL) with the lowest SL removal (2.24 ± 0.30) and SBS (8.88 ± 0.73 MPa)., Conclusion: MB-CNPs-PDT appears to be a suitable alternative to CHX for CAD disinfection as it displayed better antibacterial efficacy, SL removal, and SBS with 7th generation single bottle adhesive., (Copyright © 2024. Published by Elsevier B.V.)

Decreased nerve blood flow may be a pathogenetic factor in diabetic neuropathy. Previously it was shown that insulin treatment, commenced at the onset of streptozotocin-diabetes, prevents the development of a nerve blood flow deficit in the diabetic rat. The present study sought to determine the effect of short-term (one month) and acute (one hour) insulin reversal treatment on nerve blood flow deficits in streptozotocin-diabetes. Sciatic nerve blood flow was assessed using laser Doppler flowmetry. Treatment was initiated after one month of diabetes. One month of reversal insulin treatment ameliorated nerve laser Doppler flux (NDF) deficits; in untreated diabetic rats NDF was 51% of that in control animals (P < 0.01), in insulin-treated diabetic rats NDF was 85% of control values (P < 0.01 vs. untreated diabetic, P < 0.05 vs. control). In association with blood flow increases, we found a significant amelioration of motor (P < 0.05 vs. untreated diabetic) and sensory (P < 0.01 vs. untreated diabetic) nerve conduction velocities but not of exaggerated resistance to hypoxic conduction block. Insulin partially reversed hyperglycaemia and sciatic nerve polyol and sugar levels. In a second experiment, in rats with one month of diabetes, acute infusion of insulin led to a 47% (P < 0.001 vs. pre-insulin values) reduction of plasma glucose. This fall in plasma glucose was accompanied by a 38% (P < 0.05 vs. pre-insulin values) increase in NDF. Sensory nerve conduction velocity was marginally increased (6%, P < 0.05 vs. pre-insulin values) after insulin infusion, but motor conduction velocity was not. The data indicate that insulin can partially reverse deficits in nerve blood flow and conduction in diabetic rats.